The present invention relates to a rotor of an alternating current generator mounted on a motor vehicle, and especially to a rotor of the type having a pair of rotor segments, a bobbin disposed in the segments and a field coil wound on the bobbin.
In a conventional rotor of an alternating current generator, electrical connections between coil starting and terminating ends of a field coil wound on a bobbin and a slip-ring assembly are not sufficiently strong or resistant against vibrations, centrifugal forces produced during the operation of the generator. Further, the steps for the electrical connections are very troublesome, because, for example, an automatic welding machine can be hardly used.
Furthermore, in the conventional rotor of the type, a step for assembling a bobbin with a field excitation coil to rotor segments is not easily proceeded since much care must be taken for preventing the coil starting or terminating ends from being drawn back from the bobbin during the assembling step.
It is, therefore, an object of the present invention to provide a rotor of an alternating current generator having a bobbin of an effective structure, whereby the coil starting or terminating ends of the field coil are fixedly held in place on the bobbin to facilitate subsequent assembling steps such as a step for interposing the bobbin between the rotor segments, a step for electrically connecting the coil ends with a slip-ring assembly, and so on.
According to one aspect of the present invention, a pair of projections are integrally formed with one of the flanged portion of the bobbin, extending axially and outwardly from the flanged portion. Each of the projections is formed with an axially extending groove and a radially and axially extending slit communicating the outside of the projection with the groove over the entire axial length of the projection. Field coil terminals made of an electrically conductive flat metal strip are press-fitted respectively into the grooves of the projections. The coil starting and terminating ends are guided by and held in the slits and hung on the press-fitted terminals, whereby the coil ends are not drawn out of the bobbin. The projections with the terminals and coil ends are also press-fitted into through holes of the rotor segment so that they are further rigidly secured to the projections.
These and other objects, advantages and features of the present invention will become more apparent from the following detailed description of the embodiment when read in conjunction with the accompanying drawings.